import redis.clients.jedis.Jedis;

import java.util.HashMap;
import java.util.Map;

/**
 * 可重入锁
 */
public class RedisWithReentrantLock {

    private ThreadLocal<Map> lockers = new InheritableThreadLocal<>();
    private Jedis jedis;

    public RedisWithReentrantLock(Jedis jedis){
        this.jedis= jedis;
    }

    private Map<String,Integer> currentLockers(){
        Map<String,Integer> refs = lockers.get();
        if (refs != null){
            return refs;
        }
        lockers.set(new HashMap());
        return lockers.get();
    }




    public boolean lock(String key){
        Map<String, Integer> refs = currentLockers();
        Integer refCnt = refs.get(key);
        if (refCnt != null){
            refs.put(key,refCnt+1);
            return true;
        }
        boolean ok = this._lock(key);
        if (!ok){
            return false;
        }
        refs.put(key,1);
        return true;
    }


    private boolean unlock(String key) {
        Map<String, Integer> refs = currentLockers();
        Integer refCnt = refs.get(key);
        if (refCnt== null){
            return  false;
        }
        refCnt-=1;
        if (refCnt >0){
            refs.put(key,refCnt);
        }else{
            refs.remove(key);
            this._unlock(key);
        }
        return true;
    }

    private boolean _lock(String key){
        return jedis.set(key,"","nx","ex",5L)!=null;
    }

    private void _unlock(String key){
        jedis.del(key);
    }




    public static void main(String[] args) {
        Jedis conn = new Jedis("192.168.179.21", 6379);
        conn.select(15);

        RedisWithReentrantLock redis = new RedisWithReentrantLock(conn);
        System.out.println(redis.lock("codehole"));
        System.out.println(redis.lock("codehole"));
        System.out.println(redis.unlock("codehole"));
        System.out.println(redis.unlock("codehole"));

    }


}
